function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		header_main_over = newImage("img/header_main.jpg");
		header_main1_over = newImage("img/header_main1.jpg");
		header_left_over = newImage("img/header_left.jpg");
		header_order_over = newImage("img/header_order.jpg");
		header_price_over = newImage("img/header_price.jpg");
		header_prod_over = newImage("img/header_prod.jpg");
		header_services_over = newImage("img/header_services.jpg");
		preloadFlag = true;
	}
}